Yes, that's a good explanation of the encapsulation perspective and code. See the message I just posted for even more basic info on trying to help a cfinvoke function locate a cfc. Unless I put it in the same folder as the calling page, I get an error saying it can't be found no matter how I try to set up a path using the "source" attribute, etc.
??? Rick > -----Original Message----- > From: Mike Kear [mailto:[EMAIL PROTECTED] > Sent: Monday, June 16, 2008 12:50 AM > To: CF-Talk > Subject: Re: cfc question... > > Rick, I'm delighted to see you starting to work with the power of > CFCs. I also had the same confusion as you did at first. The > terminology for some of these OO concepts gets a bit confusing, so > perhaps i can help you by expressing some of the ideas related without > using the teminology. > > Perhaps it might help to see your code with notation for the same thing. > ...... > > <cfset agent_info = agent.get_agent_info( #url.agent_id# ) /> > > Here you're naming a query variable "agent_info", and it's being > populated with records from a function called agent.get_agent_into() > which has been given the parameter #url.agent_id#. That's exactly > equivalent to your code: > > <cfinvoke component='agent' > method='get_agent_info' > returnvariable='agent_info' > agent_id='#url.agent_id#'> > > (Although you dont need the hash signs around the url variable, so it > would more properly be expressed: <cfset agent_info = > agent.get_agent_info( url.agent_id ) /> ) > > Compare this to something you've been using for a long time already like: > > <cfset variable1 = dateformat( createdate, "d/mm/yyyy") /> > > You dont need to know how dateformat goes about its business of > transforming your variable in order to use it. All the work is done > inside the function dateformat(). It's the same inside your function > agent.get_agent_info() > > Now the function get_agent_info() has a limited number of things it > needs to know, and doesnt care about the rest of the world. All it > wants to know is the agent_id it has to look up, and the datasource > name. It doesnt care about anything else, nor should it either. > This is the concept of 'encapsulation' which means briefly, that each > function has a specific thing it does, and it shouldnt know (or need > to know) anything except what you tell it. > > That's just like the function dateformat() that you've been using > since you started with ColdFusion so long ago. It doesnt know what > you're using the date for, where the date came from or anything else. > All it knows is you give it a date object and it gives you back a > string. > > Does that help you? > > Cheers > Mike Kear > Windsor, NSW, Australia > Adobe Certified Advanced ColdFusion Developer > AFP Webworks > http://afpwebworks.com > ColdFusion, PHP, ASP, ASP.NET hosting from AUD$15/month > > > On Mon, Jun 16, 2008 at 5:43 AM, Rick Faircloth > <[EMAIL PROTECTED]> wrote: > > Let's say I have link on a page back to itself: > > > > <a href='page.cfm?agent_id=20'>Get Agent</a> > > > > Then I have this in my page.cfm to invoke a cfc > > called 'agent.cfc': > > > > <cfinvoke component='agent' > > method='get_agent_info' > > returnvariable='agent_info' > > agent_id='#url.agent_id#'> > > > > > > My 'agent.cfc' looks like this: > > > > <cffunction access='remote' name='get_agent_info' output='0' > > returntype='query'> > > > > > > <cfargument name='agent_id' type='string' required='1'/> > > > > > > <cfquery name='get_agent' datasource='xxxxx'> > > > > select * from our_agents where agent_id = '#arguments.agent_id#' > > > > </cfquery> > > > > <cfif get_agent.recordcount> > > <cfreturn get_agent/> > > <cfelse> > > <cfreturn 0/> > > </cfif> > > > > </cffunction> > > > > Now, let's say the invocation is successful and I have extracted query data. > > I know how to access all the query data back on the calling page (it seems > > counter-intuitive that the <cfreturn> variable, 'get_agent' in my example > > above, > > is referenced or 'renamed as 'agent_info' as the returnvariable in the > > <cfinvoke>... > > why the renaming?). > > > > However, in my app I'm converting all the agent data from the query into > > session > > variables to customize my templates. > > > > Is there a way to do that in the .cfc or should I handle that back on my > > calling .cfm page? > > If I handle it in the .cfc, which I'd prefer in order to keep all > > processing out of the > > display page code, how would I return the session variables to the calling > > page? > > > > Thanks for any input! > > > > Rick > > > > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Adobe® ColdFusion® 8 software 8 is the most important and dramatic release to date Get the Free Trial http://ad.doubleclick.net/clk;203748912;27390454;j Archive: http://www.houseoffusion.com/groups/CF-Talk/message.cfm/messageid:307541 Subscription: http://www.houseoffusion.com/groups/CF-Talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.4
